Our purpose is provided state of the art fluorescence activated cell sorting technology to the investigators at NIEHS including assistance on experimental design, instrument operation, and data analysis. The lab is equipped with 4 diverse and uniquely customized instruments and 2 workstations with various flow cytometric computer programs for off line and in depth data analysis, including presentation/multi-color analysis software. Currently there are 120 individual scientists at NIEHS who are trained and have access to these instruments. Over the past year, we have accomplished 1,298 projects, including 165 physical sorts where cells were isolated for further culture, injection, or biochemical analysis. The scope of these projects cover a broad range of scientific investigation including viability assessment, fluorescent protein expression, cell size and intracellular ion analysis, immunophenotyping, cell cycle profiling, and assessment of cell death. Additionally, several specialized studies involving fluorescent resonance energy transfer (FRET), intracellular organelle function, and oxidative/phosphorylation studies have been accomplished. Specifically, we have developed new methods to determine changes in cell size to other cellular characteristics during a physiological mode of cell death known as apoptosis. In addition to the six reported publications listed in the bibliography section of this report authored or coauthored by members of the lab, flow cytometry has supported 12 additional publications over the past year in collaboration other NIEHS investigators through the use of our instrumentation.